Nucleotide sequence of cDNA encoding the precursor of the 23 kDa photosystem II protein of tomato

✍ Scribed by Scott Betts; Eran Pichersky

• Publisher: Springer
• Year: 1992
• Tongue: English
• Weight: 103 KB
• Volume: 18
• Category: Article
• ISSN: 0167-4412
• DOI: 10.1007/bf00019216

✦ Synopsis

Photosystem II (PSII) in higher plants is a multiprotein transmembrane complex residing in the thylakoids of chloroplasts. Oxygen evolution activity of inside-out thylakoid vesicles is inhibited by treatment with 250 mM NaC1, which releases water-soluble polypeptides of 17 and 23 kDa from PSII [1]. Rebinding of the purified 23 kDa protein restores activity; this observation first implicated the 23 kDa protein as a component of the oxygen-evolving complex.

The cDNA encoding the 23 kDa PSII protein from tomato (Lycopersicon esculentum) was isolated from a cDNA library probed with the corresponding cDNA from mustard (Sinapis alba) (Fig. 1). The amino acid sequence of the mature protein is 86~o identical to that for tobacco (Nicotiana tabacum) [2], also a member of the Solanaceae family. The mustard and spinach (Spinacia oIeracea) proteins share, respectively, 85 To and 81 ~o sequence identity with the tomato protein [ 3, 4].